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HydroBond 403 GB

Newton HydroBond 403 GB is a high-performance, self-healing, composite sheet membrane with exceptional waterproofing capabilities, that also provides ground gas resistance (in compliance with BS 8485:2015+A1:2019) to radon, carbon dioxide and hydrocarbon gases. When fitted above the raft support or to building line formwork, the membrane locking fleece is encapsulated into the newly placed concrete, becoming fully-engaged to prevent water tracking.

If the waterproof LDPE layer is punctured, the exposed hydrophilic coating expands, preventing water ingress and effectively sealing small holes that may be accidentally formed during fixing of the reinforcing steel or the placing and compaction of the concrete.

Newton HydroBond 403 GB is a component of the HydroBond® System that also includes post-applied waterproofing membranes, protection and drainage boards, providing a complete waterproof envelope to the structure to achieve Type A (barrier) waterproofing suitable for Grades 1, 2 and 3 as defined by BS 8102:2022. The HydroBond System is suitable for all below-ground and earth-retained structures from domestic basements to the largest civil engineering projects.

Correctly protected, the Newton HydroBond System will provide, under normal service conditions, a durable waterproof barrier for the life of the building to which it is installed; the expected lifetime of the building itself should be at least 60 years.

  • Key Benefits
  • Typical Applications
  • Suitable Substrate
  • Technical Data
  • FAQ
  • Key Benefits

    Key Benefits

    • Third-party test certification for radon, carbon
      dioxide and hydrocarbon gases
    • Full mechanical bond to concrete prevents water migration between membrane and structure
    • Hydrophilic layer provides self-healing of punctures to the membrane
    • Very flexible – Resistant to movement and fissures in substrates
    • The HydroBond System completely surrounds the structure
    • Excellent resistance to the high alkalinity of concrete

    Typical Applications

    Typical Applications

    As a continuous waterproofing and gas membrane to permanent raft and wall formwork such as the raft blinding and piled walls of reinforced concrete earth retained structures.

    Suitable Substrate

    Suitable Substrate


    • Concrete blinding
    • Compacted type 1 hardcore
    • Compacted sand

    The following can be placed above the blinding or hardcore prior to the installation of HydroBond 403 GB:


    • Existing structure
    • Secant or contiguous concrete piles
    • Metal sheet piles
    • Diaphragm walls
    • King post wall
    • Sufficiently stable ground such as clay or chalk
    • Temporary timber shuttering/formwork

    Technical Data

    Technical Data

    Installed Performance Results
    Service temperature -40ºC to +100ºC
    Adhesion to concrete 0.4 N/mm²
    Elongation at break (Machine) 57.4 (± 3.86)%
    Elongation at break (Traverse) 81.7 (± 7.79)%
    Tensile strength (Machine) 411 (± 15) mm
    Tensile strength (Traverse) 695 (±16.4) mm
    Resistance to static loading – 20 kg load Watertight
    Resistance to impact – AI plate – 200 mm drop N/A
    Resistance to impact – EPS panel – 500 mm drop N/A
    Joint strength – Glued seam 409 N/50 mm
    Resistance to tearing – Nail shank – MD** 518 N
    Resistance to tearing – Nail shank – Across 470 N
    Resistance to fire Euroclass E
    Water vapour diffusion resistance – Sd value 1000 m
    CO2 gas diffusion resistance 8.38 x10-7 m2/s
    CO2 permeability – Membrane 1.94 ml/(m²/d/atm)-¹
    CO2 permeability – Joint 20.00 ml/(m²/d/atm)-¹
    CO2 permeability – Combined
    2.02 ml/(m²/d/atm)-¹
    Radon gas diffusion resistance –
    1.0 x10-12 m2/s
    Radon gas diffusion resistance – Joint 1.5 x10-9 m2/s
    Methane permeability – Membrane 0.44 ml/(m²/d/atm)-¹
    Methane permeability – Joint 91 ml/(m²/d/atm)-¹
    Methane permeability – Combined
    6.99 ml/(m²/d/atm)-¹
    Durability against thermal ageing – 70ºC
    for 12 weeks



    What is a gas barrier?

    Gas barriers are technological solutions that have the capability to diminish or decelerate the movement of gases and vapours. The primary purpose of obstructing or lessening the migration of gas is to safeguard the contents stored on the opposing side of the barrier.

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    Our staff are able to provide guidance for projects of all sizes, whether you require some general advice about damp or waterproofing, or support with technical drawings and specifications.

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